Molecular Probes is proposing to continue development of several types of fluorescent enzyme substrates and novel included are new substrates that can detect single lacZ beta-galactosidase or GUS beta-glucuronidase transfected cells through development of a improved fluorescent substrates for detection and innovative methods for increasing the sensitivity of flow cytometric analysis are proposed. Synthesis and applications of novel probes for classification and analysis of viable blood cells are included. Some of these products have been found to be useful in identifying defects in leukocytes that relate to human Chronic Granulomatous Disease.